4:00 pm Monday, January 24, 2011Topology Seminar: Obstructions to being homology cobordant to a Seifert-fibered 3-manifold
by Daniel Tanner (Rice) in HB 427

Homology cobordism is an equivalence relation on the set of closed, oriented connected 3-manifolds. It has been known for some time that every equivalence class contains a hyperbolic 3-manifold. We prove that many equivalence classes contain no Seifert-fibered manifold by finding obstructions in the cohomology ring.